Signal for telephone-switchboards.



No. 762,337. PATENTED JUNE 14, 1904.

F. R. MOBBRTY & J. L. MoQUARRIR' SIGNAL FOR TELEPHONE SWITGHBOARDS. APPLICATION nun; JULY 2, 1002.

N0 MODEL.

flank J7 55679 3 Kim I. fl- Qmr /d, I

m: norms versus cu. PNOTD-LFTMQ. WA$N|NGTQN, o, c.

UNITED STATES i atented June 14, i904.

PATENT OEEIcE.

FRANK R. MoBERTY, OF EVANSTON, AND JAMES L. MoQU-ARRIE, OF

CHICAGO, ILLINOIS, ASSIGNORS TO WESTERN ELECTRIC COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SIGNAL 'FoR TELEPHONE-SWITCHBOABDS.

SPECIFICATION forming part of Letters Patent No. 762,337, dated June 14, 1904.

Application filed July 2, 1902. Serial No. 114,085. (No model.)

To all whom it may concern..-

Be it known that we, FRANK R. MCBERTY, residing at Evanston, and JAMES L. MOQUAR- RIE, residing at Chicago, in the county of Cook and State of Illinois, citizens of the United States, have invented a certain new and useful Improvement in Signals for Telephone- Switchboards, of which the following is a full, clear, concise, and exact description.

Our invention relates to a signal for telephone-switchbords, and has for its object to provide an improved electromechanical indicator which will be especially adapted for use as a line-signal.

In accordance with our invention a target is arranged to be moved through the agency of a magnet, and a shield is provided for concealing the target, with a second magnet adapted to effect a relative movement between the shield and the target, so that when the second magnet is excited the target is concealed independent of the condition of the first magnet. Used as a line-signal for telephone-switchboards, the first-mentioned magnet is connected in the line-circuit and the second magnet is included in a local switchboard-circuit established in closing the operators connection-switch, as in inserting a switch-plug in the terminal spring-jack of the line. Preferably the shield is movable, being normally held in a position to conceal the target when the latter is in its normal position, said shield being arranged to be moved by the second magnet into a position where it will cover the target in both the alternative positions of said target. 4

W' e will describe our invention more particularly by reference to the accompanying drawings, which illustrate the preferred embodiment thereof.

Figure, 1 is a diagram showing a telephoneline extending from a substation to a centraloflice switchboard with a portion of the operator.s plug-circuit for making connection with the line, the system being equipped with the signal device and circuits therefor in 'accordance with our invention. Fig. 2 is a detail elevation of the signal device, and Fig. 3 is a front view thereof.

The same parts are indicated by the same characters of reference in all figures,

The line-signal device, which is provided at the central ofiice to indicate calls for connection, comprises two electromagnets f g, with a target is, carried by the armature f of one of said magnets, and a movable shield 70 carried by the armature g of the other magnet. A plate 70 may be provided upon the face of the switchboard with an opening k in said plate, behind which either the target is or the shield k is displayed when the corresponding magnet is excited. Normally, however, both the shield and target are concealed by the plate 70 the parts resting as shown in Fig. l. The front of the shield k may have the same color as the front of the plate k, and the target is may have a distinctive color.

When the magnet f is excited, the armature f is attracted and raises the target 10', so that it is seen through the opening lc If now the magnet g is excited, its armature g will raise the shield between the target is and opening if, so that the shield instead of the target will be seen through said opening, While the magnet g is excited, therefore. the target is will be concealed whether the magnet f is ex cited or not, since the shield 70 covers both of the alternative positions of the target.

In Fig. 2 the parts are shown in the positions they occupy when both magnets are excited.

Our invention is especially designed to be used in combination with the line-circuit of a telephone-line controlled by the substationswitch and a local switchboard-circuit established during the temporary connection with the line at the central oflice.

As shown in Fig. 1, the telephone-line extends in two limbs l 2 from the usual substation apparatus to the poles of a permanently connected central battery I); The usual telephone-switch a is provided at the substation for controlling the flow of current in the line, and the magnet f is provided with twohigh impedance-windingsincluded,respectively, in the limbs 1 2, so that said magnet is excited while the substation telephoneswitch is closed, as during the use of the telephone. A connection terminal or springjack of the usual type is illustrated,said springjack having two line-springs connected, respfictively, with the limbs 1 2 and a third contact or thimble (2, Which is adapted to cooperate with the sleeve-contact (Z of the operators connection switch or plug in the control of a local switchboard-circuit 6 3. The operator s plug-circuit is of a well known type, such as is common in central-battery relayswitchboards. The tip and ring contacts of the plug form the terminals of link conductors 4: 5, which lead through the windings of a repeating-coil to the poles of a central battery,whieh supplies current for the telephonetransmitter of the line with which the plugcircuit may be connected.

While we have indicated two batteries each marked 7), it is understood thatin accordance with the usual practice a single battery may be employed. One pole of the battery is grounded, and the free pole thereof is connected with the third contact or sleeve of the plug and may include a supervisory signal a. A supervisory relay (1 is included in one of the main conductors of the plug-circuit in the path of current to the substation, said relay controlling a shunt about the supervisory signal, as usual.

When the subscriber desires an exchange connection, he removes his telephone from its hook, and so closes the circuit of the battery 5 through the windings of the magnet f. The armature f is thus attracted and moves the target 76 into its position of display. The operator answers the call in the usual manner by inserting her switch-plug in the springjack of the line whose indicator is displayed. The local switchboard-circuit 3 is thus com- .pleted through the windings of the magnet g and the armature r/ is attracted, whereby the shield 71: is moved up in front of the target 7:, thus efl'acing the signal. The shield if remains displayed in the opening 721 until the connection is taken down.

Having thus described our invention, we claim 1. The combination with a telephone-line extending from a substation to a connectionterminal at a central ofiice, said line having a switch at the substation controlling its circuit, of a source of current and a line-magnet in the circuit so controlled, a target adapted to be moved into a position of display by said magnet, a movable shield for the target, a second magnet adapted to move said shield into a position to conceal the target, whereby upon the excitation of said second magnet said target is concealed independent of the line-magnet, a connection-switch for engaging the terminal of the line, and a circuit of said second magnet established in closingsaid connection-switch.

2. The combination with a magnet and a target adapted to be moved thereby into a pos'ition of display, of a movable shield for the target, and a second magnet arranged to move said shield into a position to conceal the target, whereby upon the excitation of said second magnet the target is concealed independent of the condition of the first magnet.

3. The combination with amovable target, of a movable shield normally held in a position to conceal the target when the latter is in its normal position, a magnet arranged to move said target into a position of display, and a second magnet arranged to move the shield into a position covering the target in both positions of said target.

4. The combination with a telephone-line extending from a substation to a line-terminal at a central office, of a switch at the substation controlling the circuit, a line-magnet and a source of current at the central office in the circuit so controlled, a target arranged to be moved by said magnet, a movable shield normally held in a position to conceal the target, said target being moved by said magnet when excited to display a signal, a second magnet arranged to move the shield into a position to conceal the signal in both positions or" said target, a connection-switch at the central ofiice adapted for engagement with the lineterminal, and a circuit for said second magnet established in closing said connection-switch.

5. The combination with an electromagnet, of an armature therefor, a target carried by said armature adapted to be displayed when said magnet is energized, a second electromagnet, an armature therefor, and a shield carried by said armature adapted when the last-mentioned magnet is excited to cover or conceal said target.

In witness whereof we hereunto subscribe our names this Q lth day of March, A. D. 1902.

FRANK R. MOBERTY. JAMES L. MOQUARRIE.

Witnesses:

FREDERICK A. VVATKINs, HOWARD B. HoLMns. 

